Exploring Interactions Between Sex, Pain Characteristics, Disability, and Quality of Life in People With Chronic Spinal Pain: A Structural Equation Model.

In people with nonspecific chronic spinal pain (nCSP), disability and quality of life are associated with clinical, cognitive, psychophysical, and demographic variables. However, evidence regarding the interactions between these variables is only limited to this population. Therefore, this study aims to explore path models explaining the multivariate contributions of such variables to disability and quality of life in people with nCSP. This secondary analysis uses baseline data from a randomized controlled trial including 120 participants with nCSP. Structural equation modeling was used to explore path models for the Pain Disability Index (PDI), the Short Form 36-item physical (SF-36 PC), and mental (SF-36 MC) component scores. All models included sex, pain catastrophizing, kinesiophobia, hypervigilance, and pain intensity. Additionally, the PDI and SF-36 PC models included pressure pain thresholds (PPTs) at the dominant pain site (ie, neck or low back). Significant associations were found between sex, pain cognitions, pain intensity, and PPTs. Only pain catastrophizing significantly directly influenced the PDI (P ≤ .001) and SF-36 MC (P = .014), while the direct effects on the SF-36 PC from kinesiophobia (P = .008) and pain intensity (P = .006) were also significant. However, only the combined effect of all pain cognitions on the SF-36 PC was mediated by pain intensity (P = .019). Our findings indicate that patients' pain-related cognitions have an adverse effect on their physical health-related quality of life via a negative influence on their pain intensity in people with nCSP. PERSPECTIVE: This secondary analysis details a network analysis confirming significant interactions between sex, pain cognitions, pain intensity, and PPTs in relation to disability and health-related quality of life in people with chronic spinal pain. Moreover, its findings establish the importance of pain cognitions and pain intensity for these outcomes. TRIALS REGISTRATION: Clinicaltrials.gov (NCT02098005).

Persistence of post-COVID symptoms in the general population two years after SARS-CoV-2 infection: A systematic review and meta-analysis.

OBJECTIVE: This meta-analysis investigated the prevalence of post-COVID symptoms two-years after SARS-CoV-2 infection. METHODS: Electronic literature searches on PubMed, MEDLINE, CINAHL, EMBASE, Web of Science databases, and on medRxiv/bioRxiv preprint servers were conducted up to October 1, 2023. Studies reporting data on post-COVID symptoms at two-years after infection were included. Methodological quality was assessed using the Newcastle-Ottawa Scale. Random-effects models were used for meta-analytical pooled prevalence of each symptom. RESULTS: From 742 studies identified, twelve met inclusion criteria. The sample included 7912 COVID-19 survivors (50.7% female; age: 59.5, SD: 16.3). Post-COVID symptoms were assessed at a follow-up of 722.9 (SD: 51.5) days after. The overall methodological quality of studies was moderate (mean: 6/10, SD: 1.2 points). The most prevalent post-COVID symptoms two-years after SARS-CoV-2 infection were fatigue (28.0%, 95%CI 12.0-47.0), cognitive impairments (27.6%, 95%CI 12.6-45.8), and pain (8.4%, 95%CI 4.9-12.8). Psychological disturbances such as anxiety (13.4%, 95%CI 6.3-22.5) and depressive (18.0%, 95%CI 4.8-36.7) levels as well as sleep problems (20.9%, 95%CI 5.25-43.25) were also prevalent. Pooled data showed high heterogeneity (I2 ≥ 75%). CONCLUSION: This meta-analysis shows the presence of post-COVID symptoms in 30% of patients two-years after COVID-19. Fatigue, cognitive disorders, and pain were the most prevalent post-COVID symptoms. Psychological disturbances as well as sleep problems were still present two-years after COVID-19.

Prognostic Factors for Postoperative Chronic Pain after Knee or Hip Replacement in Patients with Knee or Hip Osteoarthritis: An Umbrella Review.

Knee and hip osteoarthritis are highly prevalent in the older population. Management of osteoarthritis-related pain includes conservative or surgical treatment. Although knee or hip joint replacement is associated with positive outcomes, up to 30% of patients report postoperative pain in the first two years. This study aimed to synthesize current evidence on prognostic factors for predicting postoperative pain after knee or hip replacement. An umbrella review of systematic reviews was conducted to summarize the magnitude and quality of the evidence for prognostic preoperative factors predictive of postoperative chronic pain (>6 months after surgery) in patients who had received knee or hip replacement. Searches were conducted in MEDLINE, CINAHL, PubMed, PEDro, SCOPUS, Cochrane Library, and Web of Science databases from inception up to 5 August 2022 for reviews published in the English language. A narrative synthesis, a risk of bias assessment, and an evaluation of the evidence confidence were performed. Eighteen reviews (nine on knee surgery, four on hip replacement, and seven on both hip/knee replacement) were included. From 44 potential preoperative prognostic factors, just 20 were judged as having high or moderate confidence for robust findings. Race, opioid use, preoperative function, neuropathic pain symptoms, pain catastrophizing, anxiety, other pain sites, fear of movement, social support, preoperative pain, mental health, coping strategies, central sensitization-associated symptoms, and depression had high/moderate confidence for an association with postoperative chronic pain. Some comorbidities such as heart disease, stroke, lung disease, nervous system disorders, and poor circulation had high/moderate confidence for no association with postoperative chronic pain. This review has identified multiple preoperative factors (i.e., sociodemographic, clinical, psychological, cognitive) associated with postoperative chronic pain after knee or hip replacement. These factors may be used for identifying individuals at a risk of developing postoperative chronic pain. Further research can investigate the impact of using such prognostic data on treatment decisions and patient outcomes.

Carpal Tunnel Syndrome: Neuropathic Pain Associated or Not with a Nociplastic Condition.

Carpal tunnel syndrome (CTS) has been traditionally classified as primarily a neuropathic condition with or without pain. Precision medicine refers to an evidence-based method of grouping patients based on their susceptibility to biology, prognosis of a particular disease, or in their response to a specific treatment, and tailoring specific treatments accordingly. In 2021, the International Association for the Study of Pain (IASP) proposed a grading system for classifying patients into nociceptive, neuropathic, or nociplastic phenotypes. This position paper presents data supporting the possibility of subgrouping individuals with specific CTS related-pain into nociceptive, neuropathic, nociplastic or mixed-type phenotypes. Carpal tunnel syndrome is a neuropathic condition but can also be comorbid with a nociplastic pain condition. The presence of extra-median symptoms and the development of facilitated pain processing seem to be signs suggesting that specific CTS cases can be classified as the nociplastic pain phenotype. The clinical responses of therapeutic approaches for the management of CTS are inconclusive. Accordingly, the ability to identify the predominant pain phenotype in patients with CTS could likely be problematic for producing efficient treatment outcomes. In fact, the presence of a nociplastic or mixed-type pain phenotype would explain the lack of clinical effect of treatment interventions targeting the carpal tunnel area selectively. We propose a clinical decision tree by using the 2021 IASP classification criteria for identifying the predominant pain phenotype in people with CTS-related pain, albeit CTS being a priori a neuropathic pain condition. The identification of a nociplastic-associated condition requires a more nuanced multimodal treatment approach to achieve better treatment outcomes.

Myofascial Pain Syndrome: A Nociceptive Condition Comorbid with Neuropathic or Nociplastic Pain.

Myofascial pain syndrome is featured by the presence of myofascial trigger points (TrPs). Whether TrPs are primary or secondary phenomena or if they relate to central or peripheral nervous system disorders is controversial. Referred pain, a cardinal sign of TrPs, is a central phenomenon driven by peripheral input. In 2021, the International Association for the Study of Pain (IASP) proposed a clinical criteria and grading system for classifying patients with pain on nociceptive, neuropathic, or nociplastic phenotypes. Myofascial TrP pain has been traditionally categorized as a nociceptive phenotype; however, increasing evidence supports that this condition could be present in patients with predominantly nociplastic pain, particularly when it is associated with an underlying medical condition. The clinical response of some therapeutic approaches for managing TrPs remains unclear. Accordingly, the ability to classify myofascial TrP pain into one of these phenotypes would likely be critical for producing more successful clinical treatment outcomes by a precision medicine approach. This consensus paper presents evidence supporting the possibility of subgrouping individuals with myofascial TrP pain into nociceptive, nociplastic, or mixed-type phenotype. It is concluded that myofascial pain caused by TrPs is primarily a nociceptive pain condition, is unlikely to be classified as neuropathic or nociplastic, but can be present in patients with predominantly neuropathic or nociplastic pain. In the latter cases, management of the predominant central pain problem should be a major treatment goal, but the peripheral drive from TrPs should not be ignored, since TrP treatment has been shown to reduce sensitization-associated symptomatology in nociplastic pain conditions, e.g., fibromyalgia.

Network Analysis Reveals That Headache-Related, Psychological and Psycho-Physical Outcomes Represent Different Aspects in Women with Migraine.

Evidence supports that migraine is a complex pain condition with different underlying mechanisms. We aimed to quantify potential associations between demographic, migraine-related, and psychophysical and psychophysical variables in women with migraine. Demographic (age, height, and weight), migraine-related (intensity, frequency, and duration), related-disability (Migraine Disability Assessment Scale, Headache Disability Inventory), psychological (Hospital Anxiety and Depression Scale), and psycho-physical (pressure pain thresholds -PPTs-) variables were collected from a sample of 74 women suffering from migraine. We calculated adjusted correlations between the variables by using a network analysis. Additionally, we also calculated centrality indices to identify the connectivity among the variables within the network and the relevance of each variable in the network. Multiple positive correlations (ρ) between PPTs were observed ranging from 0.1654 (C5-C6 and tibialis anterior) to 0.40 (hand and temporalis muscle). The strongest associations within the network were those between migraine attack frequency and diagnosis of chronic migraine (ρ = 0.634) and between the HDI-E and HDI-P (ρ = 0.545). The node with the highest strength and betweenness centrality was PPT at the second metacarpal, whereas the node with the highest harmonic centrality was PPT at the tibialis anterior muscle. This is the first study applying a network analysis to understand the underlying mechanisms in migraine. The identified network revealed that a model where each subgroup of migraine-related, psychological, and psycho-physical variables showed no interaction between each variable. Current findings could have clinical implications for developing multimodal treatments targeting the identified mechanisms.

Pain Extent Is Not Associated with Sensory-Associated Symptoms, Cognitive or Psychological Variables in COVID-19 Survivors Suffering from Post-COVID Pain.

We aimed to investigate the relationship between pain extent, as a sign of sensitization, and sensory-related, cognitive and psychological variables in hospitalized COVID-19 survivors with post-COVID pain. One hundred and forty-six (67 males, 79 females) previously hospitalized COVID-19 survivors with post-COVID pain completed demographic (age, sex, height, weight), sensory-related (Central Sensitization Inventory, Self-Report Leeds Assessment of Neuropathic Symptoms), cognitive (Pain Catastrophizing Scale, Tampa Scale for Kinesiophobia) and psychological (Hospital Anxiety and Depression Scale, Pittsburgh Sleep Quality Index) variables. Pain extent and frequency maps were calculated from pain drawings using customized software. After conducting a correlation analysis to determine the relationships between variables, a stepwise linear regression model was performed to identify pain extent predictors, if available. Pain extent was significantly and weakly associated with pain intensity (r = -0.201, p = 0.014): the larger the pain extent, the lower the pain intensity. No other significant association was observed between pain extent and sensory-related, cognitive, or psychological variables in individuals with post-COVID pain. Females had higher pain intensity, more sensitization-associated symptoms, higher anxiety, lower sleep quality, and higher kinesiophobia levels than males. Sex differences correlation analyses revealed that pain extent was associated with pain intensity in males, but not in females. Pain extent was not associated with any of the measured variables and was also not related to the presence of sensitization-associated symptoms in our sample of COVID-19 survivors with long-term post-COVID pain.

Understanding Sensitization, Cognitive and Neuropathic Associated Mechanisms behind Post-COVID Pain: A Network Analysis.

This study aimed to describe a network including demographic, sensory-related, psychological/cognitive and other variables in individuals with post-COVID pain after hospitalization. Demographic (i.e., age, height, weight, months with symptoms), sensory-related (Central Sensitization Inventory -CSI-, Self-Report Leeds Assessment of Neuropathic Symptoms -S-LANSS-, PainDETECT), psychological/cognitive (Hospital Anxiety and Depression Scale -HADS-A/HADS-D-, Pain Catastrophizing Scale -PCS-, Tampa Scale for Kinesiophobia -TSK-11-) and other (sleep quality and health-related quality of life -EQ/5D/5L) variables were collected in 146 COVID-19 survivors with post-COVID pain. A network analysis was conducted to quantify the adjusted correlations between the modelled variables, and to assess their centrality indices (i.e., the connectivity with other symptoms in the network and the importance in the system modelled as network). The network revealed associations between sensory-related and psychological/cognitive variables. PainDETECT was associated with S-LANSS (ρ: 0.388) and CSI (ρ: 0.207). Further, CSI was associated with HADS-A (ρ: 0.269), TSK-11 (ρ: 0.165) and female gender (ρ: 0.413). As expected, HADS-A was associated with HADS-D (ρ: 0.598) and TSK-11 with PCS (ρ: 0.405). The only negative association was between sleep quality and EQ-5D-5L (ρ: -0.162). Gender was the node showing the highest strength, closeness, and betweenness centralities. In addition, CSI was the node with the second highest closeness and betweenness centralities, whereas HADS-D was the node with the second highest strength centrality. This is the first study applying a network analysis for phenotyping post-COVID pain. Our findings support a model where sensitization-associated symptoms, neuropathic phenotype, and psychological aspects are connected, reflecting post-COVID pain as a nociplastic pain condition. In addition, post-COVID pain is gender dependent since female sex plays a relevant role. Clinical implications of current findings, e.g., developing treatments targeting these mechanisms, are discussed.

Effects of Ultrasound-Guided Nerve Stimulation Targeting Peripheral Nerve Tissue on Pain and Function: A Scoping Review.

This paper assesses the effects of percutaneous electrical nerve stimulation (PENS) on pain- and function-related outcomes by means of a scoping review of studies with single cases, case-series, quasi-experimental, and randomized or non-randomized trial designs. We consulted the PubMed, MEDLINE and EMBASE databases. Data were extracted by two reviewers. The methodological quality of studies was assessed using the Physiotherapy Evidence Database (PEDro) scale for experimental studies and the Joanna Briggs Institute (JBI) tool for case reports or cases series. Mapping of the results included: (1), description of included studies; (2), summary of results; and, (3), identification of gaps in the existing literature. Eighteen articles (five randomized controlled trials, one trial protocol, nine case series and three case reports) were included. The methodological quality of the papers was moderate to high. The conditions included in the studies were heterogeneous: chronic low back pain, lower limb pain after lumbar surgery, chronic post-amputation pain, rotator cuff repair, foot surgery, knee arthroplasty, knee pain, brachial plexus injury, elbow pain and ankle instability. In addition, one study included a healthy athletic population. Interventions were also highly heterogeneous in terms of sessions, electrical current parameters, or time of treatment. Most studies observed positive effects of PENS targeting nerve tissue against the control group; however, due to the heterogeneity in the populations, interventions, and follow-up periods, pooling analyses were not possible. Based on the available literature, PENS interventions targeting peripheral nerves might be considered as a potential therapeutic strategy for improving pain-related and functional outcomes. Nevertheless, further research considering important methodological quality issues (e.g., inclusion of control groups, larger sample sizes and comparatives between electric current parameters) are needed prior to recommending its use in clinical practice.

Bayesian Linear Regressions Applied to Fibromyalgia Syndrome for Understanding the Complexity of This Disorder.

A better understanding of the connection between factors associated with pain sensitivity and related disability in people with fibromyalgia syndrome may assist therapists in optimizing therapeutic programs. The current study applied mathematical modeling to analyze relationships between pain-related, psychological, psychophysical, health-related, and cognitive variables with sensitization symptom and related disability by using Bayesian Linear Regressions (BLR) in women with fibromyalgia syndrome (FMS). The novelty of the present work was to transfer a mathematical background to a complex pain condition with widespread symptoms. Demographic, clinical, psychological, psychophysical, health-related, cognitive, sensory-related, and related-disability variables were collected in 126 women with FMS. The first BLR model revealed that age, pain intensity at rest (mean-worst pain), years with pain (history of pain), and anxiety levels have significant correlations with the presence of sensitization-associated symptoms. The second BLR showed that lower health-related quality of life and higher pain intensity at rest (mean-worst pain) and pain intensity with daily activities were significantly correlated with related disability. These results support an application of mathematical modeling for identifying different interactions between a sensory (i.e., Central Sensitization Score) and a functional (i.e., Fibromyalgia Impact Questionnaire) aspect in women with FMS.

Understanding the interaction between clinical, emotional and psychophysical outcomes underlying tension-type headache: a network analysis approach.

OBJECTIVE: Evidence supports that tension-type headache (TTH) involves complex underlying mechanisms. The current study aimed to quantify potential multivariate relationships between headache-related, psychophysical, psychological and health-related variables in patients with TTH using network analysis. METHODS: Demographic (age, height, weight), headache-related (intensity, frequency, duration, and headache-related disability), psychological and emotional (Hospital Anxiety and Depression Scale, Pittsburgh Sleep Quality Index), psycho-physical (pressure pain thresholds [PPTs] and myofascial trigger points) and health-related variables (SF-36 questionnaire) were collected in 169 TTH patients. Network connectivity analysis was unsupervised conducted to quantify the adjusted correlations between the modelled variables and to assess their centrality indices (i.e., the connectivity with other symptoms in the network and the importance in the modelled network). RESULTS: The connectivity network showed local associations between psychophysical and headache-related variables. Multiple significant local positive correlations between PPTs were observed, being the strongest weight between PPTs over the cervical spine and temporalis area ([Formula: see text]: 0.41). The node with the highest strength, closeness and betweenness centrality was depressive levels. Other nodes with high centrality were vitality and headache intensity. DISCUSSION: This is the first study applying a network analysis to understand the connections between headache-related, psychophysical, psychological and health-related variables in TTH. Current findings support a model on how the variables are connected, albeit in separate clusters. The role of emotional aspects, such as depression, is supported by the network. Clinical implications of the findings, such as developing TTH treatments strategies targeting these most important variables, are discussed.

Clinical, Psychological, and Neurophysiological Outcomes Associated with Pain and Function in Individuals with Unilateral Plantar Heel Pain.

OBJECTIVE: To assess the potential relationship of demographic (age, gender, body mass index, height, weight), clinical (affected side, duration of symptoms, health-related quality of life), psychological (depressive levels), or neurophysiological (pressure pain sensitivity and number of trigger points) variables with foot function and pain intensity in patients with unilateral plantar heel pain (PHP). METHODS: Fifty-four patients with PHP (48% females) were recruited. Data on demographics, months with pain, time in standing position, depression, pressure pain thresholds (PPTs), number of trigger points, health-related quality of life, function, and pain intensity were collected. A multivariable correlation analysis was performed to determine the associations among the variables, and a regression analysis was conducted to explain the variance in function and pain intensity. RESULTS: Pain intensity was negatively correlated with symptom duration and calcaneus bone PPT and positively associated with gender, time in standing position, and number of trigger points. Function was negatively correlated with PPTs on the calcaneus bone, the flexor digitorum brevis muscle, and the abductor hallucis muscle and with quality of life and was positively correlated with age, gender, and depressive levels. Stepwise regression analyses revealed that 60.8% of pain intensity was explained by female gender, calcaneus PPTs, time in a standing position, and function. Furthermore, gender, quality of life, age, depressive levels, and calcaneus bone PPTs explained 52.4% of function variance. CONCLUSIONS: This study found that demographic, clinical, psychological, and neurophysiological variables can mutually interact to affect function and pain intensity in patients with unilateral PHP. These findings could guide clinicians in the identification, prevention, and treatment of PHP risk factors.

Cross-sectional area of the cervical extensors assessed with panoramic ultrasound imaging: Preliminary data in healthy people.

BACKGROUND: Studies analyzing morphometry of neck extensor musculature have mostly used Magnetic Resonance Imaging (MRI). Panoramic Ultrasound View could be used for obtaining high-quality 2D cross-sectional images with a wide field of view more cost-effectively imaging acquisition by creating an automatic construction of 2D cross-sectional images. OBJECTIVE: To measure neck extensors cross-sectional area (CSA) using panoramic ultrasound view in healthy subjects. DESIGN: Cross-sectional study. METHODS: Panoramic B-mode ultrasound images of the neck extensor muscles at C4/C5 level were acquired in 25 healthy subjects (40% women, mean age: 24 ± 5 years) by an experienced assessor. The CSA of the upper trapezius, splenius (layer), semispinalis (layer), multifidi, short rotators, and levator scapulae were calculated. The relative percentage in the total neck extensor muscle volume of each CSA was also determined. Sex and side-to-side comparisons were conducted. RESULTS: Men showed larger CSAs than women in all muscles (all, P < 0.01). No side-to-side differences were found in either men or women (all, P > 0.05). Significant positive associations between CSA with weight (r: 0.654 to 0.375, P < 0.01), height (r: 0.386 to 0.581, P < 0.05), and BMI (r: 0.369 to 0.563, P < 0.05) were found. Men showed greater percentage of upper trapezius and semispinalis muscle layers than women (P < 0.01), whereas women had a greater percentage of levator scapulae muscle than men (P < 0.01) from the total volume of the neck extensors. No side-to-side differences were found either. CONCLUSIONS: The current study describes CSA, as assessed with panoramic ultrasound view, of the neck extensors in healthy people. Men exhibited greater CSA than women with no side-to-side differences.

Intra-rater and inter-rater reliability of rehabilitative ultrasound imaging of cervical multifidus muscle in healthy people: Imaging capturing and imaging calculation.

BACKGROUND: Studies have analyzed muscle morphometry of cervical multifidus by using ultrasound imaging, but its reliability is not clearly determined. OBJECTIVE: To investigate intra- and inter-rater reliability of imaging capturing (probe assessment/patient positioning) and imaging calculation (scan assessment) of cervical multifidus cross sectional area (CSA) by considering the assessor's experience in asymptomatic individuals. DESIGN: Reliability study. METHODS: The CSA of C4/C5 cervical multifidus was assessed in 16 asymptomatic subjects. Two examiners performed the imaging capture and also repeated the procedure (probe placement/patient positioning) twice with a 10-min period between each. Other two raters conducted imaging calculations of CSA. Intra-examiner imaging capturing reliability, each rater (experienced and novice) calculated multifidus CSA of both images obtained by each examiner. Inter-examiner imaging capturing reliability, each rater calculated the CSA obtained by each examiner at the first imaging attempt. For imaging calculation reliability, each rater calculated multifidus CSA of all images captured by both examiners. Intra-class correlation coefficients (ICC) and standard error of measurement (SEM) were calculated. RESULTS: Intra- (ICC3,1 0.988-0.996, SEM 0.3%-0.7%) and inter- (ICC3,2 0.958-0.965, SEM 2.6%-3.2%) examiner reliability of imaging capturing was excellent. Intra- and inter-rater reliability of imaging calculation was also excellent for both raters (experienced/novice). No significant differences between experienced or novice examiners or testers were found. CONCLUSIONS: This study found that intra- and inter-examiner/rater reliability of imaging capturing (probe assessment/patient positioning) and imaging calculation (scan assessment) of the cervical multifidus CSA at C4/C5 level was excellent in asymptomatic subjects.